The present invention relates to a manual grinder for foodstuffs in the form of grains, such as spices.
Grinders or mills already exist that are designed to be mounted on the necks of receptacles that have been previously filled with grains in order to form a method of packaging and distribution ready for use.
However, those grinders are made in the form of at least two independent parts which need to be assembled together in a specific order before or after being mounted on the receptacle, thus implying manufacturing operations that are laborious and thus expensive.
Also, the operation of positioning the two moving parts that perform grinding relative to each other is awkward and difficult to check, and if it is not done correctly, there can arise serious problems in operation.
Furthermore, the fineness and thus the quality of grinding depends mainly on the narrowness of the intermediate zone between these two parts, which means that the assembly must be fitted together accurately and it is difficult to achieve this in automatic and reproducible manner on assembly and packaging lines.
An object of the present invention is to resolve these technical problems in satisfactory manner.
According to the invention, this object is achieved by means of a manual grinder for mounting on the neck of a receptacle for foodstuffs in the form of grains, the grinder being characterized in that it comprises firstly a fixed ring provided with a flange for supporting it on the receptacle, which flange is downwardly extended by an inner sleeve that is engaged in said neck and that presents a toothed inner side wall, and secondly a cap rotatably mounted on said neck covering said ring and including a peripheral skirt radially connected to a central bushing having a toothed outer side wall that is engaged coaxially in said sleeve, so as to define between them a peripheral grinding zone
According to an advantageous characteristic, said skirt is radially connected to said bushing by means of bridges leaving between them outlet orifices for the ground foodstuff.
Preferably, said bridges lie in the plane of the top face of said cap.
According to another characteristic, said peripheral skirt is provided with snap-fastening members for cooperating with complementary members carried by the neck of the receptacle.
In order to improve the flexibility of the skirt, it is possible also to provide local thinning of its wall thickness.
According to another characteristic, said support flange has locking members for locking it in rotation and designed to co-operate with complementary members carried by the neck of the receptacle.
In a particular variant, said locking members are constituted by a continuous series of teeth carried by the bottom face of said flange and designed to become locked on at least one complementary tooth formed on the top rim of the neck.
Preferably, each of said teeth of the flange and of the neck is constituted by a sloping face for absorbing rotary forces, and by a steeper face for transmitting said forces.
In another variant, said sleeve is radially clamped against the inner wall of said neck.
According to other characteristics, said rotary cap has an annular guide groove slidably receiving the peripheral edge of said flange, and the top face of said flange is provided with an annular rib that comes into sliding contact with the bottom face of the cap.
The grinder of the invention makes it possible automatically to obtain proper relative positioning of the moving cap and the fixed ring without it being necessary to provide indexing of these two parts relative to each other.
Furthermore, the ring is locked against rotation on the receptacle without sliding, thus providing good mechanical efficiency.
In addition, grinding quality is guaranteed by forces being transmitted automatically from the receptacle (which is rotated while in an upside-down position) to the toothed sleeve of the inner ring which then moves slightly closer to the toothed bushing of the cap which is held stationary by the user.
The grinder of the invention is thus constituted by only two parts which are easy to fabricate and to assemble and which can be installed quickly and securely on the receptacle while providing the assembly with an overall shape that is very ergonomic and compact.